1. Fedor
2. Nog
3. Werdum
4. Cain
5. JDS
After the top 5 that's where it gets confusing
6. Barnett - Went 18-1 before the Crocop losses, I think Crocop was just a fighter that had his number and he matched up badly with. He had wins over Schilt (two) Couture and Severn in this time, winning the UFC title and winning and defending the Pancrase title twice.
7. Crocop - his career really went downhill at the end but he had a staggering amount of wear and tear after over 100 combined fights by the time he was in the UFC. Barnett, Coleman, Wand, Randleman, Igor, Yoshida, Saku, Herring, Alex E. Crocop in his day was the Liddell of the heavyweights, perfect sprawl and brawl and unmatched standing. If he had of hung the gloves up earlier he would have been top 5 but he fought too late damaging his legacy.
8. Coleman - won 2 UFC tournaments and the UFC title in his 1st 6 fights
9. Bas Rutten - 22 fight win streak. 10 years without a loss
10. Overeem - wins over Arlovski, Lesnar, JDS, Mir, Werdum, Nelson, Rogers, Hunt, Sergei, Belfort, Igor.. Overeem has a lot of losses but his wins are some of the most impressive in heavyweight history.
As much as I love Hunt he would bearly crack the top 20 in my eyes.